Just bought this monitor yesterday I have a rtx2070 super and cannot figure out how to enable 4k at 144hz I turned the settings on on the OSD and have both DP cables plugged in windows is now saying I have 2 monitors plugged in and my pc keeps flashing black every time I hit a key or move my mouse or anything then back to my desktop every time i try and move my mouse or anything please help as this was a very expensive purchase for me and I would like to know how to truly enable this feature